TB2901HQ Просмотр технического описания (PDF) - Toshiba

Номер в каталоге

Компоненты Описание

производитель

TB2901HQ

Maximum Power 47 W BTL × 4-ch Audio Power IC

Toshiba 

Large current capacity switch

Battery

VCC

VCC

– Conventional Method –

TB2901HQ(O)

Relay

Battery

From

microcomputer

Small current capacity switch From microcomputer

Battery

Stand-By VCC

Stand-By VCC

– Standby Switch Method –

Battery

Figure 3

3. Muting Function (pin 22)

Audio muting function is enabled when pin 22 is Low. When the time constant of the muting function is

determined by R1 and C4, it should take into account the pop noise. The pop noise which is generated when

the power or muting function is turned ON/OFF will vary according to the time constant. (Refer to Figure 4

and Figure 5.)

The pin 22 is designed to operate off 5 V.

Moreover, this terminal (pin 22) serves as the source switch of current of an internal mute circuit. And it is

designed so that the discharge current of this terminal (pin 22) may serve as 200 µA. The outside pull-up

resistor R1 is determind on the basic of this value.

ex) When control voltage is changed in to 6 V from 5 V.

6 V/5 V × 47 k = 56 k

To obtain enough mute attenuation, a series resistor, R1 at pin 22 should be 47 kΩ or more.

5V

22

R1

C4

1 kΩ

Mute ON/OFF

control

20

VCC = 13.2 V

0 f = 1kHz

RL = 4 Ω

VOUT = 20dBm

−20

ATT – VMUTE

−40

−60

−80

−100

−120

0

0.5

1

1.5

2

2.5

3

Pin 22 control voltage: VMUTE (V)

Figure 4 Muting Function

Figure 5 Mute Attenuation − VMUTE (V)

4

2004-10-15

Share Link: